Objective To analyze the differences and the similarities of the chromatic characteristics between human lung adenocarcinoma cell lines A549 and H322.Methods Cytological samples of A549 and H322 cells were prepared from drop sections stained with hematoxylin and eosin,and papanicolaou staining.Computer image analysis of the cytological samples was performed to determine the chromatic parameters,including three primary colors of cytoplasm ( Rp,Gp,Bp) and their coefficient ( rp,gp,bp),three primary colors of cell nuclei ( Rn,Gn,Gn) and their coefficient ( rn,gn,bn).Results The measurement results of chromatic parameters showed that in the cytology by drop sections stained with hematoxylin and eosin and papanicolaou staining,the values of Rp,Rn,Gn,Bp,Bn,rp,rn,gp,gn,bp and bn had significant difference between A549 andH322 cells ( P < 0.01) ;Conclusions There are significant differences between the chromatic parameters of Rp,Rn,Gp,Gn,Bp,Bn,rp,rn,gp,gn,bp and bn of A549 and H322cells,not only in HE-stained drop sections,but also in Papanicolaou staining ( except for Gp,,rn,gp in hematoxylin and eosin and Rp,Bp,rp,gp in papanicolaou staining ).These differences could be used for the identification between A549 andH322 cells.